Rapid fabrication of NiFe(OH)_x/Fe_0.2Co-Se complexes for oxygen evolution reaction electrocatalysis

Exploiting the inexpensive and efficient oxygen evolution reaction (OER) electrocatalysts is crucial for improving the efficiency of electrocatalytic water splitting (EWS), since the slow 4-electron OER process is a rate-limiting step in EWS. Herein, we prepared the NiFe(OH)(x)/Fe0.2Co-Se complexes on carbon paper (CP) via an easy two-step electrochemical deposition strategy. By varying the doping amount of Fe and the deposition time of Fe0.2Co-Se, the OER property of NiFe(OH)(x)/Fe0.2Co-Se/CP was optimized to the best: only requiring low overpotentials of 243 and 277 mV at the current density of 20 and 100 mA/cm(2) (j(20) and j(100)) and a small Tafel slope of 36.8 mV/dec, along with a terrific long-term durability in 1 M KOH. According to the experimental results, the rich exposed active sites, improved intrinsic site activity and enhanced electrical conductivity lead to the superior OER performance. Our work will provide some inspiration for designing other metal selenide/hydroxide heterostructures for other energy conversion or storage applications. (C) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.